INTEGRATING RESTORATION APPROACHES TO IMPROVE RECOVERY OF ENDANGERED SALMONIDS IN THE PACIFIC NORTHWEST, USA

Two approaches to ecological restoration planning, limiting-factors analysis and process-based restoration, are commonly invoked by efforts to recover endangered salmonid species throughout the Pacific Northwest of North America. Limiting-factors analysis seeks to identify physical habitat limitations to fish production that may be addressed by habitat restoration projects; it is known as the “Field of Dreams” hypothesis (i.e., if you build it, they will come). Process-based restoration, in contrast, assumes that protection and/or restoration of watershed-scale processes is the only sustainable means to create the dynamic habitats that support salmon populations (although ignorance of the precise mechanisms by which this creation will occur is rarely considered problematic). The limiting-factors approach to river restoration has long been the norm for government agencies and private practitioners alike; we also recognize many recent restoration efforts that tout the conceptual benefits of process-based restoration but nonetheless maintain a traditional focus on the laborious enumeration of site-specific habitat features and the subsequent construction of any such features that seem to be “missing.”

Initiatives in the Columbia River basin (northwestern USA), however, are now making a more conscious effort to integrate these two restoration approaches. They embrace the overriding importance of supporting key watershed processes to achieve long-term restoration goals, allocating substantial resources to that end, even as they also seek to identify (and ultimately rebuild) those habitat types whose shortfalls demonstrably limit salmonid populations. These initiatives highlight the challenge facing practitioners of river restoration: how to avoid simply repackaging a familiar suite of analyses and actions in an updated wrapper, but rather to follow the broader guidance provided by process-based restoration, not only during recovery planning but also through implementation of on-the-ground actions. We encourage a realignment of the restoration community to truly embrace this multi-scalar, process-based view of the riverine landscape as the most likely path to sustainable, long-term restoration of these systems and the species they support.